Helical-shift multispeed transmission



Feb. 6, 1951 v. D. BEHN 4 2,540,858

HELI CAL- SHIFT MULTISPEED TRANSMISSI O N Filed Nov. 9, 1945 2 Sheets-Sheet l INVENTOR.

VIE'I'EIFi D. BEHN.

'BYW

ATTORNEY Feb. 6, 1951 V. D. BEHN HELICAL-SHIFT MULTISPEED TRANSMISSION Filed NOV. 9, 1945 2 Sheets-Sheet 2 INVENTOR. VIET DR ATTORNEY D. BEHN.

Patented Feb. 6, 1951 HELICAL-SHIFT MULTISBEED TRANSMISSION Victor D. Behn, Glen Rock, J., assignor to Corporation, a corporation Wright; Aeronautical o Ne i r Application November 9, 1945; Serial No. 6273578 13. Claims.

1 'Ijhis ipvention relates to Inulti-speed trans-. miss and is particularly directedto; trans: missions of a typ iliustrated: in an application,

Serial No. 492,166, filed by R. Chilton, issued as-Patent No. 2,400,539 on May- 21, 194.6. In said? Chilton patent a speed ratio shift member is: shittable along helical; splines: on a drive shaft for selective engagement with any one of a plurality of gears. In addition, said.- Chilton patent, lockingmeanscomprising; a pal-ref lock-.. ing; members are provided to releasably lock the shift member; against. movement in bothdirections while. said shift member is. engaged with. any one; of said gears. It is an objectof this, invention to provide a relatively. simple locking means for such. a. shift member. invention comprises a single lockingmember which is adapted: to lock the shift memberagainst; movement: in both directionswhile the. shift member is engaged. with. a gear.

(Other objects of this invention will become apparent upon reading the annexed detailed. de-.. scription in connection with the drawing in which:

Figure. 1 is a, schematic axial. sectional. View through a transmission embQdyingthe invention;

Figure 2,. is an enlarged sectional View takenalong line 2 :2 oi Figure 1;

Figure. 3 is a. developed sectiontaken along line 3m3, of Figure 1;

Figure. 4. is a, developed section illustrating amodiiieation of Figr m 3,; and

Figure 5 is an axial. sectional View similar tov Figure l but; of a further modification.

The invention is, described in connection. with a transmission for an, engine driven automotivevehicle, but, as will appear, the. invention is; not limited. to, this. specific application. Also, as. used in, the specification. and claims, unless; otherwise.

specif ed, the term speed ratio always. refers tatheratiQof thespeed of the transmission out-. putshaftto thespeed. of. the transmission input shagtt,

Referring to. the drawing, an engine drive it are spaced around the-shaft it and are journaled in fixed; bearingdiaphragms I8 and 26-. securedto the transmission housing. Each lay shaft; H5 is provided; with a plurality of gears: 22; 24, 26, and? 2 8tight1y: secured to: the layshafts by a 31h As illustrated, the gears 2 2A, 26 and:

Specifically, the

28 are, of diiferent pitch diameters and: are respectivelyengaged- With nested clutch gears 3-2, 34;, 3,6; and 38 having similar internal clutch teeth 40;. The layshafts It are each. also pro-. vided with a pinion gear 52 disposed in, meshing engagement with a gear i l splined to a drive transmitting or output shaft 46. The speed ratio; shift member I4 is provided with clutch teeth 4-8 adapted to selectively engage the clutch teeth, 40: of; the clutch gears 32, 34, 36 and 318; With, this construction, the speed ratio of the drive connection between the input shaft l0 and the output shaft 46 depends on which of theclutch gears is engaged' by the shift member. number of speed ratios may be provided merely.- by providing the appropriate number of clutch gears for engagement by the shiftmember.

As illustrated, the pinion gears 22;, 24, Eli and 28; are of; progressively decreasing pitch diameter; Accordingly, the gears 22 provide the first or lowspeed ratio between the input and output shafts and the gears 24,, 26 and 28 provide progressively higher speed ratios-namely, second, third andfourth speeds. Since the pinion gears 2-2, 24, 26

26 and 28 are rotationally rigid With their associated ,viding the higher speed ratios.

la'yshafts, the clutch gears 32, 3d, 36;. and 3.8; always simultaneously rotate at different speedswith; the clutch gears providing the lower speed ratios rotating faster than the clutch gears pro- Thus, the. clutch gear 3% always rotates faster than the clutch gear- 34, the clutch gear 34 always rotates: faster than the clutch gear- 35; etc.

The; shift member 5 4 is provided with one or more ratchets 59 on its left side as viewed in Figure; 1 and one or more ratchets 52 on its right side. Asillustrated, the ratchets 5i! and. 52 are mounted' inpairson a common bolt 54 with the noses or working ends of theratchets 59 and- 52 pointing in opposite directions, the nose of each, ratchet 5B pointing in the direction of rotation oi the: shaft, Ill and, the nose of each ratchet 52;

pointing against this direction of rotation. Springs 55 are provided for outwardly urging the working ends of" the ratchets, In addition the Working end" ofeach ratchet is disposed in alinement with the remote side of one of the clutch teeth; 48; on the shift member Hi.

With the. arrangement so far described, if the clutch, teeth 43 of the shift member M are disposed between two adjacent gears-for example, 32. and SL-and with the shaft Iii rotating clockwise, as viewed in Figure 2, at a speed intermediate the gears 32 and 34, the clutch teeth 48:

of" the. gear 32 will over-run the ratchet 5!] and 3 the clutch teeth of the gear 34 will under-run the ratchets 52. Now, if the speed of the shaft I should start to increase beyond the speed of the clutch gear 32, the ratchet so will immediately engage the clutch teeth 40 of the gear 32 and shift the shift member I4 to the left along its helical splines to bring its clutch teeth 48 into meshing engagement with the clutch teeth 40 of the gear 32. Because of the alinement of the teeth 48, when the ratchets 50 engage the clutch teeth 48, the clutch teeth 48 will be in alinement with the spaces between the clutch teeth 4!] whereby these teeth engage without clashing.

Similarly, if the speed of the shaft l0 should start to fall below that of the gear 34, the ratchets 52 will immediately engage the clutch teeth 40 of the gear 3e and shift the shift member M to the right along its helical splines into engagement with the gear 34. Here again, because of the alinement of the ratchets 52 with'the teeth 48, the teeth 48 and 68 engage Without clashing. The structure so far described is quite similar to that disclosed in the aforementioned application of R. Chilton.

In order to releasably lock the shift member It in engagement with any one of the clutch gears 32, 34, 35 and 38, the shift member is provided with axial splines 58 on its back. An annular unitary locking member 66 is disposed with its axial splines 52 in sliding engagement with said splines 58. In addition, the locking member so has axial splines 54 arranged for selective engagement with axially spaced sets of splines '66 on the shaft iii. With this construction, when the locking member 60 is in engagement with one of the sets of splines St on the shaft I El, the shift member is held against movement along its helical splines and, when the locking member moves out from engagement with one of the sets of shaft splines 56, the shift member M is freed for move ment along its helical splines. Thus the locking member 6! with its spaced sets of axial splines 55, can lock the shift member is against movement along its helical splines l2 at spaced stations along the shaft I 9 corresponding to the spacing of the gears 32, 3 3, 38 and 38.

The sets of splines 55 are staggered as seen in Figure'3. Thus, as illustrated, each set of splines 65 is rotationally displaced relative to an adjacent set of splines so that the individual splines of each set are disposed in alinement with the spaces between the individual splines of the adjacent sets. 'With this construction, the looking member 60 can not shift axially directly from one set of splines 56 into engagementwith an adjacent set but, instead, must first shift axially to bring its spline 55 into the space between said one and adjacent sets of splines 56, then rotate into alinement with said adjacent splines 66 and then shift axially into engagement therewith. Thispath of the locking member splines 64 is illustrated by the dashed lines 53 in Figure3. The angular offset of adjacentsets of splines 56 ismade equal to the angular rotation of the shift member id in moving from engagement with one 'set of clutch teeth 43 to an adjacent set in orderthat the single unitary locking member 6% can lock the shift member I 4 in engagement with any'of the gears 32, 3s, 36 or 3B. As illustrated, the axial spacing of the splines 65 is equal to the axial spacing of the clutch teeth it. This axial spacing obviously is not essential to the aforedescribed angular offset of adjacent splines 66 but is desirable since as a result the splines 58 4 and 52 always occupy the same relative position in each gear ratio thereby reducing the necessary length of the splines 58.

The locking member to is connected to a speed ratio control rod 19 through a two-way resilient connection. To this end, the rod '56 is provided with a pair of spaced flanges i2 and M against which a pair of slidable washers l6 and it are respectively urged. by an interposed spring 852. A housing 82 surrounding the washers and i8 is provided with inturned flanges 84 and 35 havinga spacing equal to that of the flanges i2 and id andrespeotively engagea-ble by the washers i5 and it, The locking member 55! is provided with an annular groove B55 and an arm 55 rigid with the housing 32 extends into this annular groove. The control rod 16 is provided with a V plurality of spaced notches 52 having a spacing 92 thereby compressing the spring til. spring so, through the washer l8 and flange 86,

corresponding to the spacing of the splines 65. A spring-pressed detent 94 is adapted to selectively engage any one of the-notches 92 in the shift control rod. The spacing of the notches 92 defines the extent to which the control rod lll' must be shiftedin going from one gear ratio to another and the particular notch 92 engaged by the spring-pressed detent 94 determines the speed ratio position of the control rod it. As illustrated, the control rod is in its first speed ratio position and may be shifted to the right to its second. third and fourth speed ratio positions.

In Figure 1, the transmission is in first or low speed ratio and the drive connection from the shaft it to the output shaft 45 includes a set of splines E6, the locking member tit, the shiftmemher it, clutch teeth 48 and inland gears 32, 22,

t2 and 44. When a shift to second speed is desired, the operator moves the control rod it to the right until the detent 94 engages the second notch The urgesthe housing 82 and locking member so to the right to follow upithe movement of the control rod Mi, but the torque on the locking member splines prevents the locking member from 45- following thisshift movement. The operator then reduces the engine torquefor example, by closing the engine throttle or opening or short circuiting the ignition jcircuit-whereupon the spring at shifts the locking member to the right until its splines s4 abut against the adiacent set of shaft splines 66. This shift movement of the locking member is approximately equal to onehalf the shift movement of the control rod so that the spring 8i! still urges the locking member to the right. The shift member hi is now free to move along its helical splines and, as the speed of the shaft ll! decreases, the shift member moves. into the space between adjacent clutch gears 32,

and 3 The operator keeps the engine power down until the speed of the shaft Iii starts to drop below the speed of the second speed clutch gear 3 whereupon theratchets 52 immediately.

shift the shift member into engagement with this clutch gear. As soon as this takes place, the locking member splines 54 become alined with the spaces between the next set of shaft splines 58, whereupon the spring 3Q completes the shift omens;

a-tornoyt restoresathezensinetooweirandrther rans missionrooenates seconds soeedi, 'RQrShiftiT-ilflil'l: seoondspeedi-into thirctspeed theaoneratm-moycsa thetcontrol rot-1J1! to. thezrightluntilitha detentak engages-thenexitnotchrsz andrtherensineinower is controlled, as im the: previoushr; described: 111 shift, tolcompletez the: shift: into third speed=., In third speed, the! shift; member: A! is engaged; with: thaclutch gear. 36y andsthedoching memben splines. 54: are engagedlwithlthathirdsetof shaft splines so 'ascountedz 1 11011147115? lettinliiguret 1.

Assuming that the transmission; is. in. third; peed. and that. the: openatorl -wantst ts sh-itt. dorm torsecondzsh he controkrod. 110.. islshittedrto; the leiitluntil theadetenttfls engagestthonextnotchi 9.2: thereby comoressing: the opting; an. The. ooerratorthen decreasesthea enginepcmeit int thecase of: an uol-shifthand wheo'the;driuingrtorquel on the locking: member splines decreases sufli ciently; the Soringt 811;; shifts; the; housing 82 ancl locking member: 6.0 axially to; the: lofts until its splines 64; abut: against the: second set; of splines- 56 as counted from the left in Eigune. 1*..1 'Bhs-top erator; then, restores, the; engine; power to; speed up the shaft. to: whereupon the shiftnmember; It moves. to; the; left alon s? helical? soiincs an ;v

when. the speed of; the shaft; I it starts; tor cxceecl that: of: the. second; speed: clutch. gear 34,; th

Y ratchet; 5cshifts the; member: I14 aloha itsr This,

helical-1. splines into engagement. tl ierewitirv movement. 01% the shirt" member: rotati'srelw alines; the locking member spline 54 with; said; Second; set. of shaft: splines: 66. whereuponE the; spring; 50 axially shirts: the lockin member: into n agement: therewith; to; comnletew-the shift; follow movement; of; the locking members. The shift member: is now locked: into: en a ement with the second; spcedi gear. aeainstzshitmmovement in both: directions along: its; helical; splines:

Summarizin a; speediratio shift: isae ec ed. or moving the control rod H! from one; soeedgratioi position. to the? nextraodr them decreasing: th power of the: engine; When. theztohoue: onvthe lockinevmember-fin redueesgsuifieientlr: the sprin Bil shirts theloeking member out; from i s; ore

viously: engaged: set. of: splines; 631'.v whereupon the shift member.- M: is free: to move along its: heli. cal. splines, engine power is now restored to accelerate the driving shaft in to therspeedxofi' the flasterrmovhigherspeedprartimclutch geamtozba emetagedr'I-fhetr.

is, after the locking member-'50: frees: the: shift-2: member 1-4, the shitmmembenratchets: move: the shift: member alongsits; helical splines: inter ine gagement with the: selected: gear: when,. its he case of a down-shift, the: speed. of the? shaft 1:0 starts to exceedthatzofthc: selected'i earrarnda. in. the case: offan: upsshi-tt', whom speed or; th shaft it; starts;- to. falll: belowtthat; of the: selected. gear:

The engine power: may: be automatically 6.011% trolled-e. g., by manipulation oi the: engine: throttle or ignition circuit-43oz the. end. that. the: opertaorneed? only move: the control rod; 110; to effect-.ashift- Asillustrateds Figure. 1 means: are provided to automatically: control; the enginepower in the mannerdescribed*( by" controllinga; ground on the engihetigmtion circuit. To this; end, a wire SE is connected into. theengine igni tion circuit and a pair of flexible contact 9&1 and, we are:- connected: to; wireand 62;.-

the; case: of: a: downrshifrtl the 6'; tend intolthehousins 82.:- through; nsulation; flh. 'Eho: housing; 82a: andswashers nd .8. are? con inuously grounded. asschematically indicated at Lilla. In the; case of a, down-shift, upon move-m mentmf; the rod, lvll to the-left, the contact arm Eigurelt With thiszarrangement; as soonasthe looking membersplines: til move out from engagement with the shaft splines. the ground. is; removed from the: ignition circuit, thereby; restoring: the engine power.

The, spacing: between: the: contact arm. 98- and the: end. ofthe Washer we. is less than. one-halfw thezspaoing of the. note; es 9,2 onthe control rod mately one-halt. it shift movement 1301 the: next;

highelz'g'ear ratio. However, the point. at which the engine pervert-is, out. oft, when'ashift is; in

itiastedi a movement of the-control rod 'lfl, is;

not. critical. Now when the locking member 55513112188; 5 1 move outv from engagement With; the

shaftsolinesrtt the Washer. litand oontactarm 9.8, remain. in. eng1agement and it is notuntil after the shiftmemher iii has moved; intoengagement with: a selected clutch gear andlthe locking mem bar has started to move into engagement with the. corresponding splines 66.- that the washer: l6 and; contaotarmrfifilseparate to remove-the ignis tion. ground, whereupon th engine power is; restored... Therefore, Withthecontact:armsSB and Lilli-arranged: asdescribecl, the operator needonly moire. the, control. rodit? from one: speed ratio oositionto thenext, the remainder of the operation bein entirelyautomatic;

With. the structure of. Figures. l to 3, after; the, looking; member solines es shift. out from engagement withone of the sets ofsplines 66, the; shiftcmember. Lei tree to move; in either direction along its helical splines. According-1y; itis necessary. that. the; control of the: engine power be. properly. coordinated with the movements of the locking member. in order toieffect, a desired shift, Suppose-, for example; a down-shift has, been initiated, by movement f he con rol. rod H! to. tholei-t, butthe engine power isnot properlyrestored. at, the time the locking member splines 64. shift. out, from enga ement with. one; off the. sets of splines 65,.then, the output shaft; 5E mighhover -run. the input shaft and cause the shift. member to; shift, in up-shift. direction to, the. next. higher clutch gear, thereby rota--. tiyely alining. the locking member splines M with the, adjacent. set. of sglines 65 whereupon the. spring 36, would. complete the shift, movement of the loekinsi member The transmissiolrwould than. be in the next. higher-gear; ratio althougha. clown-shift.- had; been; intended.. To positiyely preventa Wrong shift as; a result of [tnimproper coordination. of theene ine powerwith movements of, the locking member the selle -1e sets. Sit; be. termed. so that each line to on the locking, member; has. cnlyon sossil le: p h. f mov ment roleitio to, the sets of splines. 5%. Such as con. strum ion; is illustlza (1-. in; Figure it In Figure Lethe; selinefsets tilt and splin s H2? respectively: correspond: to; the. spline: sets; 66.: amt

the locking member spline64 of Figure 3. In Figure 4, adjacent spline sets IIII are rotatively displaced approximately one-fourth (instead of one-half as in Figure 3) of the angular spacing of the individual splines of each set. V In addition, each of the splines H9 is provided with a projection II4 extending axially into the space between each set of these splines. The modification of Figure 4 is otherwise identical with the structure of Figures 1 to 3. With this construction, the locking member splines II2 can only move relative to the spline sets III along the path indicated by the dashed lines N6 of Figure 4, and, therefore, the shift member I4 can only rotate in the desired direction when freed by the locking member. Accordingly, with the construction of Figure 4, when the locking member splines IIZ have been initially moved in an upshift direction into the space between adjacent sets of splines IIIl, the shift can be completed only by an up-shift movement of the member I4 and vice Versa.

Obviously, the positions of the splines 54 and 66 could be reversedthat is, the splines 54 may be formed on the shaft II) for selective engage ment by a plurality of sets of splines 66 formed internally on the locking member 55. It is also within the scope of this invention to place the spaced spline sets on the shift member instead of on the input shaft. Such a construction is illustrated in Figure 5. In this modification, an input shaft I26 is provided with axial splines I22 and helical splines I24 and a shift member I25 is slidable along the helical splines I24 and is selectively engageable with clutch gears I28, I30, I32 and I34 as in Figure 1. Also, as in Figure 1, the shift member has ratchets adapted to cooperate with the clutch gears for moving the shift member along its helical splines. The shift member is provided with spline sets I36 having a spacing equal to a spacing of the clutch gears. is provided with splines I49 engageable with the axial shaft splines I22 and with the spline sets I 36. The relation between the sets of splines I35 and the locking member splines I42 essentially is the same as that illustrated in Figure 3 or Figure 4.

A speed ratio control rod I44 is connected with the locking member I38 through a two-way resilient connection including a spring I46. As illustrated, this connection is similar to the resilient connection between the control rod It and the locking member 6% in Figure l. The control rod I44 has a notch I46 engageable by a springpressed detent I46 to define an intermediate position of the control rod. The control rod is movable in each direction from the intermediate position until its head I55 engages stop shoulders I52 or I54. It is essential that the range of movement of'the control rod from its intermediate position be greater than the necessary movement of the locking member I38 so that its splines I42 move into the space between 'adjacent sets of splines I36 to free the shift member from movement along its helical splines.

The clutch gears I28, I35, I32 and I34 respectively correspond to the clutch gears 32, 34, 36 and 33 of Figure 1 and therefore, as illustrated in Figure 5, the transmission is in low or first A locking member I38 locking'member shifts to the left to bring its splines between the first and second sets of ther movement of the rod I44 by the locking member I38. ,Further movement of the locking member by the shift member compresses the spring I45 and when the shift member I26 moves into engagement with the second speed gear I38, the locking member splines I42 are then in alinement with said second'set of splines I whereupon the spring I shifts the locking member to the left into engagement with said splines I35 to complete the shift. I

To effect a down-shift, the control rod I44 is moved to the right against the stop I55. As in Figures 1 to 3, the remainder of a down-shift is similar to an up-shift except the shift and looking members now move in directions opposite to their corresponding movement in the case of an "up-shift and the engine power is not restored until the shift member engages the next lower speed ratio gear. v

' Instead of eiTecting shift movements by controlling the engine power, it is within the scope modifications.

'of this invention to provide a hydraulic coupling or friction clutch between the input and output shafts in parallel with the clutch gears and shift member and then controlling this coupling or clutch to effect the shift movements as fully disclosed in the aforementioned application of Roland Chilton.

. While I have described my invention in detail in its present preferred embodiment, it will be obvious to those skilled in the art, after understanding my invention, that various changes and modifications may be made therein without departing from the spirit or scope thereof. I aim in 'the appended claims to cover all such I claim as my invention: 7 1. In a multi-speed transmission, a drive transmitting member having helical splines, a speed ratio shift member movable along said helical splines, at least three axially spaced gears selectively engageable by said shift member for 7 providing said transmission with a corresponding number of speed ratios, and a' unitary locking member adapted to lock said shift member against movement in both directions along said helical splines while said shift member is in engagement with anyone of said gears.

2. In a multi-speed transmission, a drive transmitting member having helical splines, a speed ratio shift member movable along said helical splines, at least three axially spaced gears selectively engageable by said shift member for providing said transmission with a corresponding number of speed ratios, and a unitary locking member engageable with said drive transmitting and shift members to look said shift member against'movement in both directions along said helical splines while said shift member is in engagement with any one of said gears.

3'. In a multirspeed transmission, a drive agsaopats "transmitting member having "helical splines and axial splines,=a speedratidshift member movable along "said helical splines and having axial splines, at least 'three axially spaced gears selectively engageable by said shift member for providing said transmission with a correspond- 'ing number of speed ratios,-anda locking member having axial splines engageable with the axial splines "onsaid drive and-shift members,

" the axial splines on one of said members comprising a plurality of axially spaced "sets f "splines equal "in number to *the number 01' said gears and being selectively engageable by the co operatingaxial splines to ioclcsaid shift member inengagement with any one of said gears.

In a 'multi-speed transmission, a drive transmitting member having helical splines, a speed --ratio shift member movable along said helicalsplines; at least' three axially spaced gears selectively engageable bysaid shift member for providing said transmission with a correspondingnumber of speed ratios, and meansforlock- 'ing saidshiit member inengagement-with any -'one-ofsaidgears,-'said means comprising-a locking member having axialsplinesarranged-to engage axial splineson said-shift member and axial splines on-said drive transmitting member, the

axial splines .on "one ,of .said ,members comprising a plurality of axially spaced sets of splines equal inanumber to :ith'e number ofssaid gears with each set of splines being rotativelydisplacedout of alinement-relati-vetoadjacent setslby an angle equal to the angle of rotation of the shift mem ber'inmoving from one-of said gears to'an-adj acentgear.

5. =In amul-ti-speed-transmission, a drivetransmitting member having helical splines, a speed ratio shift member movable along said helical splines, at least three axially spaced gears selectively engageable by said shift member for providing said transmission with a corresponding number of speed ratios, and means for locking said shift member in engagement with any one of said gears, said means comprising a locking member having axial splines arranged to engage axial splines on said shift member and axial splines on said drive transmitting member, the splines on one of said members comprising a plurality of axially spaced sets of splines equal in number to the number of said gears with the space between said spline sets being greater than the length of the splines engageable therewith and with each set of splines being rotatively'displaced out of alinement relative to adjacent sets by an angle equal to the angle of rotation of the shift member in moving from one of said gears to an adjacent gear.

6. In a multi-speed transmission, a drive transmitting member having helical splines, a speed ratio shift member movable along said helical splines, a plurality of axially spaced gears selectively engageable by said shift member for providing said transmission with a plurality of speed ratios, and means for locking said shift member in engagement with any one of said gears, said means comprising a locking member having axial splines arranged to engage axial splines on said shift member and axial splines on said drive transmitting member, the axial splines on one of said members comprising a plurality of selectively engageable axially spaced sets of splines having space between adjacent sets suificient to permit relative rotative movement of the axial splines selectively engageable therewith, each of said sets of splines being rotatively displaced out of alinement -relative to tadiacent sets by 'an angle .equal 'to the'angle of=rotation of -the shift member in moving fromwone of-said gears to anmadjacentgear, and axial projections on splines of i 5 each of said sets to conflne the splinesselectively :engageable therewithto only: one path of :movement relative thereto.

7. din amulti-speed transmission, adidvetransshitting 1 member :having helical splines, a speed ratio shift member movable along said helical splines, aplurality:ofaxiallyspaced gears selectivelylengageable by said shift memberior pro- ,viding: said transmission with a plurality of i speed :ratios, and means for locking said shift member 1 in engagement with it anyone of said gears, said means comprisinga locking member having axial splines arranged i to i engage I axial splines on said shift unember and axial splines .on said drive transmitting member the axial splines on one of "said memberscomprising a plurality of selecitively engageable axiallyspaced sets of splines having space between adjacent sets su'flicient to permit relative rotative movement of the axial splines selectively ':engageable therewith, each of said set-of splines being rotativelydisplaced out of alinementrelative toadj acentsets by an angle 3 equal "to the 1 angle of rotation of the shift member in 'moving from one of said gears'to an adjacent gearpthe splines of eachset and the-splines engageable therewith being so formed that there isbutpnepa'thof relative movement therebetween.

8. In a multi-speed transmission, a drive trans- .mitting' member having helical-splines and a plus rality i of axiallyspaced sets of axial splines, a

speed ratio shiftmembermovable along said helical splines :and having axial splines, a plurality nf-axially spaced gears selectively engageable by said shift member for providing said transmission 40 with a plurality of speed ratios, and a locking member engageable with the axial splines on said shift member and selectively engageable with said sets of splines for locking said shift member in engagement with any one of said gears, each of said sets of splines being rotatively displaced out or" alinement relative to adjacent sets by an angle equal to the angle of rotation of said shift member in moving from one of said gears to an adiacent gear.

9. In a multi-speed transmission; a drive transmitting member having helical splines and axial splines; a speed ratio shift member movable along said helical splines and having axial splines; at least three axially spaced sets of gears selectively engageable by said shift member for providing said transmission with a corresponding number of speed ratios; and means for locking said shift member in engagement with any one of said gears, said means comprising a locking member having axial splines engageable with the axial splines on said drive and shift members, the engageable axial splines on said locking member and on one of the other members comprising a single set of splines on one of said latter two members selectively engageable with a plurality of axially spaced sets of splines on the other of said latter two members, said plurality of axially spaced sets of splines being equal in number to the number of said gears.

10. In a multi-speed transmission; a drive transmitting member having helical splines and at least three axially spaced sets of axial Splines; a speed ratio shift member movable along said helical splines and having axial splines; at least 7 three axially spaced gears equal in number to 1L the number of said axially spaced sets of splines, said gears being selectively engageable by said shift member for providing said transmission with a corresponding number of speed ratios;

"and a locking member having a set of axial splines engageable with the axial splines on said shift member and having another set of axial splines selectively engageable with said axially spaced sets of splines for locking said shift mem- 7 her in engagement with any one of said gears, each of said sets of axially spaced sets of splines being rotatively displaced out of alinement with adjacent sets by an angle equal to the angle of rotation of said shift member in moving from one of said gears to an adjacent gear.

11. In a multi-speed transmission; a drive transmitting member having helical splines and axial splines; a speed ratio shift member movable along said helical splines and having axial splines; at least three axially spaced gears selectively engageable by said shift member for providing said transmission with a corresponding number of speed ratios; and means for locking said shift member in engagement with any one of said gears, said means comprising a looking member having axial splines engageable with the axial splines on said drive and shift members, the engageable axial splines on said locking member and on one of the other members comprising a single set of splines on one of said latter two members selectively engage.- able with a plurality of axially spaced sets of splines on'the other of said latter two members whereby movement of said locking member to disengage said single set of splines frees said shift member for movement along its helical splines, said plurality of axially spaced sets of splines being equal in number to the number of i said gears and the splines of each said set being rotativelydisplaced out of alinement with th splines of the adjacent sets by an angle equal to the angle of rotation of the shift member in moving from one of said gears to the adjacent gear. r

12. In a multi-speedtransmission as recited in claim 11 in which the splines of said single set have an axial length which is less than the axial space between adjacent sets of said plurality of axially spaced sets of splines.

13. In a multi-speed transmission as recited in claim 11 and including means for automatically moving said shift member out from en- 7 gagement with any one'of said gears when the driving torque therebetween becomes substantially zero and for automatically moving said shift member into engagement with an adjacent gear upon speed synchronims therewith;

REFERENCES CITED The following references are of record in the file of this patent: 7' V UNITED STATES PATENTS Number Name 7 Date 35 2,045,835 Coen -c June 30, 1936 2,248,133 snow July 8, 1941 2,400,539 Chilton May 21, 1946 

